Multipurpose Wafer Metrology System
Quality of silicon wafer plays an essential role on semiconductor manufacturing, defected silicon wafers will reduce the manufacturing yield or reduce the quality of the device. However, inspection the quality of silicon wafers requires multiple equipment which reduces the efficiency and increases the cost. Our goal is to develop an optical system that evaluates the wafer quality such as contamination, defect, and deformation with one single scan to improve the wafer inspection efficiency.
- Zhou, Fengfeng, Siying, Chen, Xingyu, Fu, Martin BG, Jun. “Real-time monitoring of the interelectrode gap during electrochemical machining processes using a smart machine tool equipped with an optical fiber Fabry-Pérot interferometer: Principle and application”. Mechanical Systems and Signal Processing 211. (2024): 111245.
- Zhou, Fengfeng, Xingyu, Fu, Siying, Chen, Jung-Ting, Tsai, Martin BG, Jun. “Analytic Spectra of Fabry–Pérot Interferometers for Hilbert Transform and its Application in Distance Monitoring”. Journal of Lightwave Technology 43. 3(2025): 1007–1016.
- Zhou, Fengfeng, Siying, Chen, Semih, Akin, Theodore, Gabor, Martin BG, Jun. “Real-time monitoring of thin film thickness and surface roughness using a single mode optical fiber”. Mechanical Systems and Signal Processing 224. (2025): 112219.
Product-Centered Manufacturing
We are developing product-level close-loop manufacturing systems by monitoring the status of workpiece in real-time. Conventional close-loop control systems monitor the status of machine tools like most CNC machines. We dedicated to bridge the gap between the machine tool and the product using our optical monitoring technology. With our advanced optical monitoring platform, we send the product information into the control system to improve the system intelligence and product quality.
- Zhou, Fengfeng, Xingyu, Fu, Siying, Chen, Changheon, Han, Martin BG, Jun. “Three-Dimensional Profile Reconstruction and Internal Defect Detection of Silicon Wafers Using Cascaded Fiber Optic Fabry–Pérot Interferometer and Leaky Field Detection Technologies”. Journal of Manufacturing Science and Engineering 146. 7(2024): 070907.
- Zhou, Fengfeng, Xingyu, Fu, Siying, Chen, Martin BG, Jun. “Detection and identification of particles on silicon wafers based on light scattering and absorption spectroscopy and Machine learning”. Manufacturing Letters 35. (2023): 991–998.
Fundamental Research
We are actively working on fundamental research about optical metrology theories, optical signal analysis theories, and AI models to improve the robustness, efficiency, and accuracy of optical monitoring platforms. Fundamental research is the brain of optical monitoring platforms and therefore plays an essential role of the system performance. A general theory is applicable to all conditions, while a theory designed for specific applications will improve the system performance. We have developed theories to analyze interference spectrum of Fabry–Pérot interferometers (FPIs) which allows the highly sensitive FPIs being used in harsh environments but maintain their high accuracy and precision. We also developed optical theories allowing optical sensors to conduct multiple tasks at the same time.
- Zhou, Fengfeng, Siying, Chen, Xingyu, Fu, Martin BG, Jun. “Real-time monitoring of the interelectrode gap during electrochemical machining processes using a smart machine tool equipped with an optical fiber Fabry-Pérot interferometer: Principle and application”. Mechanical Systems and Signal Processing 211. (2024): 111245.
- Zhou, Fengfeng, Xingyu, Fu, Siying, Chen, Jung-Ting, Tsai, Martin BG, Jun. “Analytic Spectra of Fabry–Pérot Interferometers for Hilbert Transform and its Application in Distance Monitoring”. Journal of Lightwave Technology 43. 3(2025): 1007–1016.
- Zhou, Fengfeng, Siying, Chen, Semih, Akin, Theodore, Gabor, Martin BG, Jun. “Real-time monitoring of thin film thickness and surface roughness using a single mode optical fiber”. Mechanical Systems and Signal Processing 224. (2025): 112219.